Automatic control of a power tailgate under external loading

ABSTRACT

Embodiments of a system for controlling a vehicle power tailgate are described. The system includes a motor operably connectible to a tailgate to open and close the tailgate, a processor, and a memory communicably coupled to the processor. The memory stores a tailgate control module including instructions that when executed by the processor cause the processor to, responsive to a value of a motor speed parameter being above a predetermined motor speed threshold and a value of a motor acceleration parameter being above a predetermined motor acceleration threshold during opening of a tailgate, control operation of the motor to apply a braking force to the tailgate.

TECHNICAL FIELD

The embodiments disclosed herein relate to vehicles with tailgates and,more particularly, to tailgate control systems for automatically openingthe tailgates and automatically closing the tailgates.

BACKGROUND

Many vehicles include tailgates. The tailgate is rotatably connected tothe vehicle and is movable between closed positions and open positionsto serve as a closure panel for a rear portion of the vehicle. Many oftoday's vehicles have power tailgates included as part of power tailgatesystems. The power tailgate system includes motor-driven tailgateactuators for the tailgates, and motor-driven latch actuators for thelatch assemblies. By the operation of the tailgate actuators and thelatch actuators, the power tailgate system automatically opens thetailgate and automatically closes the tailgate. Tailgate openingcommands to the power tailgate system may be initiated by a user using aswitch inside the vehicle or a keyfob.

During use, a power tailgate mounted on a vehicle such as a pickup truckmay be subjected to loading for which the tailgate was not designed. Forexample, portions of cargo items may exert forces on an inner wall or ona top surface of a closed tailgate. If a load of sufficient magnitudecontinues to act on the tailgate after tailgate opening is initiated, itmay cause the tailgate opening speed to increase to the point where thepower tailgate and/or other elements of the power tailgate system becomedamaged during opening. Furthermore, a user operating the tailgate maynot be located where he can see the cargo bed or tailgate. Thus, he mayinitiate an opening command without seeing that a load is acting on theclosed tailgate and without being able to estimate the magnitude of theload.

SUMMARY

In one aspect of the embodiments described herein, a system forcontrolling a vehicle power tailgate is provided. The system includes amotor operably connectible to a tailgate to open and close the tailgate,a processor, and a memory communicably coupled to the processor. Thememory stores a tailgate control module including instructions that whenexecuted by the processor cause the processor to, responsive to a valueof a motor speed parameter being above a predetermined motor speedthreshold and a value of a motor acceleration parameter being above apredetermined motor acceleration threshold during opening of a tailgate,control operation of the motor to apply a braking force to the tailgate.

In another aspect of the embodiments described herein, a method isprovided for controlling a vehicle power tailgate system including amotor operably connectible to a tailgate to open and close the tailgate.The method includes a step of, responsive to a value of a motor speedparameter being above a predetermined motor speed threshold and a valueof a motor acceleration parameter being above a predetermined motoracceleration threshold during opening of a tailgate, controllingoperation of the motor to apply a braking force to the tailgate.

In another aspect of the embodiments described herein, a non-transitorycomputer-readable medium is provided for controlling operation of avehicle power tailgate system including a motor operably connectible toa tailgate to open and close the tailgate. The medium storesinstructions that when executed by one or more processors cause the oneor more processors to, responsive to a value of a motor speed parameterbeing above a predetermined motor speed threshold and a value of a motoracceleration parameter being above a predetermined motor accelerationthreshold during opening of a tailgate, control operation of the motorto apply a braking force to the tailgate.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate various systems, methods, andother embodiments of the disclosure. It will be appreciated that theillustrated element boundaries (e.g., boxes, groups of boxes, or othershapes) in the figures represent one embodiment of the boundaries. Insome embodiments, one element may be designed as multiple elements ormultiple elements may be designed as one element. In some embodiments,an element shown as an internal component of another element may beimplemented as an external component and vice versa. Furthermore,elements may not be drawn to scale.

FIG. 1A is a block diagram showing elements of a vehicle incorporating apower tailgate system, including a powered tailgate, a motor, and atailgate control module used for controlling operation of the tailgate.

FIG. 1B is a rear perspective view of a vehicle including a truck bedhaving a tailgate shown in an open position, and incorporating a powertailgate system in accordance with an embodiment described herein.

FIG. 1C is a perspective view of a portion of the vehicle of FIG. 1B,showing an actuator, crank, and rotatable element of the power tailgatesystem mounted in the vehicle.

FIG. 1D is a perspective view of a portion of a tailgate and a walldefining the truck bed, showing a tailgate-side latch assembly includinga latch for latching the tailgate and a vehicle-side striker for thelatch.

FIG. 2 portrays the tailgate actuator using a cross-sectional view takenalong the line 2-2 in FIG. 1C, showing the motor included as part of thetailgate actuator in an implementation in which the tailgate actuator isa motor-driven spindle drive.

FIG. 3 is a schematic partial cross-sectional side view of the vehicleof FIG. 1B showing one possible application of a power tailgate systemin accordance with an embodiment described herein.

FIG. 4A is a schematic diagram showing one example of application of abraking force to a tailgate.

FIG. 4B is a schematic diagram showing another example of application ofa braking force to a tailgate.

FIG. 4C is a schematic diagram showing yet another example ofapplication of a braking force to a tailgate.

FIG. 5 is a schematic view of one embodiment of a portion of a motorcircuit used to apply a short circuit to the motor.

FIG. 6 is a flow diagram illustrating operation of a system forcontrolling a vehicle power tailgate in accordance with an embodimentdescribed herein.

DETAILED DESCRIPTION

A vehicle includes a power tailgate system with a power tailgate and oneor more motor-driven tailgate actuators configured to automatically openand close the tailgate responsive to commands initiated by a user.Control per the user commands is implemented by a tailgate controlmodule. The control module may be configured to control automaticoperation of the tailgate when an external load is applied to thetailgate when the tailgate is closed. More specifically, the tailgatecontrol module may, responsive to a tailgate opening command, implementan “unsupervised mode” of automatic tailgate control whereby thetailgate may be opened or remain closed depending on the magnitude ofthe external load, and in cases where a user initiating the openingcommand may not be located in a position to visually inspect thetailgate prior to opening. If the tailgate is automatically opened underthe external load, the opening speed may be monitored during opening. Ifthe opening speed becomes excessive, the control module may controloperation of the tailgate actuator to apply braking forces to slow thedescent of the tailgate and prevent damage to the power tailgate system.

Referring to FIG. 1A, an example of a vehicle 100 is illustrated. In oneor more implementations, the vehicle 100 is pickup truck with a reartailgate that may be automatically lowered (i.e., “opened”) and raised(i.e., “closed”). The terms “open”, “opened”, “opening”, etc. and“lower”, “lowered”, “lowering”, etc. may be used interchangeably hereinas applied to the tailgate. Similarly, the terms “close”, “closed”,“closing”, etc. and “raise”, “raised”, “raising”, etc. may be usedinterchangeably herein as applied to the tailgate. The vehicle 100includes various elements. It will be understood that in variousembodiments it may not be necessary for the vehicle 100 to have all ofthe elements shown in FIG. 1A. The vehicle 100 can have any combinationof the various elements shown in FIG. 1A. Further, the vehicle 100 canhave additional elements to those shown in FIG. 1A. In somearrangements, the vehicle 100 may be implemented without one or more ofthe elements shown in FIG. 1A. While the various elements are shown asbeing located within the vehicle 100 in FIG. 1A, it will be understoodthat one or more of these elements can be located external to thevehicle 100.

Additionally, it will be appreciated that for simplicity and clarity ofillustration, where appropriate, reference numerals may have beenrepeated among the different figures to indicate corresponding oranalogous elements. In addition, the discussion outlines numerousspecific details to provide a thorough understanding of the embodimentsdescribed herein. Those of skill in the art, however, will understandthat the embodiments described herein may be practiced using variouscombinations of these elements.

Part of the exemplary passenger vehicle 100 is shown in FIG. 1B. Asshown, the vehicle 100 is a pickup truck. The vehicle 100 includes anexterior and a number of interior compartments. In the illustratedpickup truck configuration of the vehicle 100, the compartments includean open-topped bed 102 for carrying cargo. In addition to the bed 102,the compartments may include a passenger compartment, an enginecompartment and the like. Among other things, the vehicle 100 mayinclude seats, a dash assembly, an instrument panel and the like housedin the passenger compartment. In addition, the vehicle 100 may includean engine, a transmission and the like, as well as other powertraincomponents (such as wheels, for example) housed in the enginecompartment and elsewhere in the vehicle 100. The wheels support theremainder of the vehicle 100 on the ground. One, some or all of thewheels may be powered by the remainder of the powertrain components todrive the vehicle 100 along the ground.

The vehicle 100 may include a body 104 that forms the exterior anddefines or otherwise encloses the bed 102 and the other compartments. Inrelation to the bed 102, the body 104 includes a deck or cargo bed 106,two sides 108, a bulkhead 110 and a rear end 112. At the rear end 112,the body 104 defines a tailgate opening 114. Likewise, the body 104,including but limited to the sides 108, renders surrounding body 116that frames the tailgate opening 114. The tailgate opening 114 opensbetween the bed 102 and the exterior. Relatedly, as part of the rear end112, the body 104 includes a tailgate 118 corresponding to the tailgateopening 114.

As shown with reference to FIGS. 1B and 1C, the tailgate 118 serves asclosure panel for the bed 102. The tailgate 118 is pivotally connectedto the surrounding body 116 for movement, relative to the tailgateopening 114, between a closed (or “up”) position and an open (or “down”)position through a range of partially-open positions. In FIG. 1C, thetailgate 118 is shown in the closed position. In the closed position,the tailgate 118 is positioned over the tailgate opening 114, with theperiphery of the tailgate 118 adjacent to the surrounding body 116, andthe tailgate 118 in alignment with the surrounding body 116. In FIG. 1B,the tailgate 118 is shown in the open position. In the open position,the tailgate 118 is positioned away from the tailgate opening 114, whichallows access to the bed 102 from the rear of the vehicle 100. In FIG.1D, the tailgate 118 is shown in a representative partially-openposition. In the partially-open positions, the tailgate 118 is betweenthe closed position and the open position.

As shown with particular reference to FIGS. 1B and 1C, in relation toopening the tailgate 118 and closing the tailgate 118, the vehicle 100includes a hinge assembly 120, and an in-bed tailgate actuator 122.Serving, at least in part, as a basic hinge, the hinge assembly 120 runsbetween the bed 102 and the tailgate 118. The hinge assembly 120connects the tailgate 118 to the bed 102, and supports the tailgate 118from the bed 102 for rotational movement between the closed position andthe open position. The tailgate actuator 122 corresponds to the hingeassembly 120 and may be housed, in whole or in part, in the bed 102.From inside the bed 102, the tailgate actuator 122 is connected with thetailgate 118 through the hinge assembly 120. Although the vehicle 100,as shown, includes one hinge assembly 120, and one tailgate actuator122, it will be understood that this disclosure is applicable inprinciple to otherwise similar vehicles including one or more hingeassemblies 120, and one or more tailgate actuators 122.

Referring to FIG. 1C, in one or more arrangements, the hinge assembly120 may include a rotatable element 301 structured for transmittingrotational force to the tailgate. In one or more arrangements, therotatable element may be rotary through-bed torque shaft incorporatedinto the hinge assembly 120 for operable connection with the tailgate.In other arrangements, the rotatable element may be another rotatableportion of the hinge assembly structured for operable connection withthe tailgate, depending on the particular hinge assembly design. Therotatable element 301 may be axially aligned with the pivotal movementof the tailgate 118, and supported from the bed 102 for axial rotation.The rotatable element 301 may support the tailgate 118 for rotationabout an associated rotatable element rotational axis 399. Moreover, thehinge assembly 120 may also include a pivotal in-bed crank 307 operablyconnected to the rotatable element 301 along the rotational axis 399 ofthe rotatable element 301 so that a rotation of the crank 307 produces acorresponding rotation of the rotatable element 301 about the axis 399(i.e., rotating the crank 307 15° about the rotatable element rotationalaxis 399 produces a corresponding rotation of the rotatable element 30115° about the axis). From outside the bed 102, the rotatable element 301may be connected to and support the tailgate 118 from the bed 102. Frominside the bed 102, the tailgate actuator 122 is connected between thebed 102 and the crank 307. Moreover, the bed 102, the tailgate actuator122 and the crank 307 serially share pivotal connections. The rotatableelement 301 may transmit torque and rotation associated with the pivotalmovement of the tailgate 118 between the tailgate and the crank 307. Theterm “operably connected,” as used throughout this description, caninclude direct or indirect connections, including connections withoutdirect physical contact. Similarly, elements described as being“operably connectible” are elements that can be connected directly(through direct physical contact) or indirectly, through other,physically intermediate element(s).

With the bed 102, the tailgate actuator 122 and the crank 307 seriallysharing pivotal connections, from between the bed 102 and the crank 307,as the product of extending and retracting as described herein, thetailgate actuator 122 is operable to pivot the crank 307 against the bed102. With the tailgate 118, the rotatable element 301 and the crank 307serially sharing rotary connections, as the crank 307 pivots, therotatable element 301 axially rotates, and, as the rotatable element 301axially rotates, the tailgate 118 pivotally closes, pivotally opens, andotherwise pivotally moves between the open position and the closedposition.

In one or more arrangements, the hinge assembly may be structured asdescribed in pending commonly-owned U.S. patent application Ser. No.16/883,246, the disclosure of which is incorporated by reference hereinin its entirety.

The vehicle 100 may include a tailgate actuator 122. The tailgateactuator 122 may be connected to the energy system 150 as describedherein. Moreover, the tailgate actuator 122 may be connected with thetailgate 118 through the hinge assembly 120 and its rotatable element301. Through the hinge assembly 120, the tailgate actuator 122 may beoperable to open the tailgate 118, close the tailgate 118 and otherwisemove the tailgate 118 between the closed position and the open positionusing electrical energy from the energy system 150. Although the vehicle100, as shown, includes one tailgate actuator 122, it will be understoodthat this disclosure is applicable in principle to otherwise similarvehicles including one or more tailgate actuators 122.

As shown with particular reference to FIG. 2 , in one implementation,the tailgate actuator 122 may be a motor-driven spindle drive. Thetailgate actuator 122 may include a two-piece telescoping or otherwiseextensible housing 200. The housing 200 may include a tubular base 202,a tubular slide 204, and a sliding overlap 206 therebetween. Inside thehousing 200, the tailgate actuator 122 may include axially aligned itemsfor converting rotary movement into linear extension and retraction. Inparticular, the tailgate actuator 122 may include a fixed motor 210, afixed reduction drive 212, a rotary screw 214, a fixed nut 216, and aspring 218. The motor 210 and the reduction drive 212 may be securedwith the base 202, the nut 216 may be secured with the slide 204, andthe screw 214 may run through the nut 216. The base 202 and the nut 216may support the screw 214 for axial rotation, including powered axialrotation by the motor 210 through the reduction drive 212. In oneimplementation, the reduction drive 212 may be a planetary reductiondrive. For instance, the reduction drive 212 may be a multistageplanetary reduction drive. In one implementation, the screw 214 may be aball screw, and the nut 216 may be a ball nut.

The motor 210 may be operable to drive the tailgate actuator 122 toextend and retract. In particular, the motor 210 may be operable tospin, and thereby power the axial rotation of the screw 214 through thereduction drive 212. As the screw 214 axially rotates, the nut 216axially moves along the screw 214 and, as the nut 216 axially movesalong the screw 214, the base 202 and the slide 204 are alternatelydrawn apart and drawn together. As the base 202 and the slide 204 aredrawn apart, the tailgate actuator 122 is extended. Alternately, as thebase 202 and the slide 204 are drawn together, the tailgate actuator 122is retracted.

From inside the bed 102, the tailgate actuator 122 is configured toreach between the bed 102 and the crank 307. As the product of extendingand retracting, the tailgate actuator 122 is operable to pivot the crank307 against the bed 102. Likewise, to allow the tailgate actuator 122 toextend and retract in association with pivoting the crank 307 againstthe bed 102, the bed 102, the tailgate actuator 122 and the crank 307serially share pivotal connections. Accordingly, the bed 102 and thetailgate actuator 122 are configured to make a pivotal connection withone another. In particular, the bed 102 may include a bracket-mountedball stud 350, the tailgate actuator 122 includes a ball socket 352, andthe ball stud 350 and the ball socket 352 are configured to make aball-and-socket connection with one another. Moreover, the crank 307 andthe tailgate actuator 122 are configured to make a pivotal connectionwith one another. In particular, the crank 307 includes the ball stud348, the tailgate actuator 122 includes a ball socket 354, and the ballstud 348 and the ball socket 354 are configured to make aball-and-socket connection with one another.

In one or more arrangements, the actuator 122 may be structured asdescribed in previously referenced U.S. patent application Ser. No.16/883,246.

Moreover, as shown with particular reference to FIG. 1D, the vehicle 100may include one or more tailgate-side latch assemblies 130. Each latchassembly 130 may include a striker chute 132 and a corresponding latch134 for latching the tailgate 118. Relatedly, the vehicle 100 mayinclude one or more vehicle-side strikers 136 corresponding to thestriker chutes 132 and the latches 134. Each latch assembly 130 isconnected to the tailgate 118. Each latch assembly 130 may be housed, inwhole or in part, in the tailgate 118. For instance, each latch assembly130 may be housed in the tailgate 118, and connected to the tailgate118, as a unitary module. Each striker 136 is connected to thesurrounding body 116. Although the vehicle 100, as shown, includes twolatch assemblies 130 and two strikers 136, it will be understood thatthis disclosure is applicable in principle to otherwise similar vehiclesincluding one or more latch assemblies 130 and one or more strikers 136.

For each corresponding striker chute 132, latch 134 and striker 136, thestriker chute 132 opens to the tailgate 118 for passing the striker 136into and out of the tailgate 118. The latch 134 is movable, relative tothe striker chute 132, in a latching direction and in an unlatchingdirection between an unlatching position and a latching position. InFIG. 1D, the latch 134 is shown in the unlatching position. In theunlatching position, the latch 134 aligns with the striker chute 132 forpassing the striker 136 into and out of the tailgate 118. In thelatching position, the latch 134 crosses the striker chute 132 forcapturing the striker 136 within the tailgate 118. Accordingly, thelatch 134 latches the tailgate 118 to the surrounding body 116 againstthe striker 136.

The latch 134 may be activated for non-revertible movement in thelatching direction. When the tailgate 118 is being closed, the latch 134functions as the tailgate 118 is moved to the closed position, andafterward, when the tailgate 118 is in the closed position. With thetailgate 118 in the open position, the latch 134, having previouslyunlatched the tailgate 118, is in the unlatching position. To close thetailgate 118, the latch 134 is activated for non-revertible movement inthe latching direction. As the tailgate 118 is moved to the closedposition, the striker 136 passes into the tailgate 118 through thestriker chute 132. As it passes into the tailgate 118, the striker 136moves the latch 134 in the latching direction to the latching position,and the latch 134, unable to move in the unlatching direction to theunlatching position, latches the tailgate 118 to the surrounding body116 against the striker 136.

In addition, the latch 134 may be deactivated for movement in theunlatching direction. When the tailgate 118 is being opened, the latch134 functions as the tailgate 118 is moved to the open position. Withthe tailgate 118 in the closed position, the latch 134, havingpreviously latched the tailgate 118, is in the latching position. Toopen the tailgate 118, the latch 134 is deactivated for movement in theunlatching direction. As the tailgate 118 is moved to the open position,the striker 136 passes out of the tailgate 118 through the striker chute132. As it passes out of the tailgate 118, the striker 136, incombination with a bias for movement in the unlatching direction, movesthe latch 134 in the unlatching direction to the unlatching position,and the latch 134 unlatches the tailgate 118 from the surrounding body116 from against the striker 136.

The vehicle 100 may include one or more latch actuators 154 for thelatch assemblies 130. Each latch actuator 154 corresponds to a latchassembly 130, and may be housed, in whole or in part, in the tailgate118. For instance, each latch actuator 154 may be housed in the tailgate118, and connected to the tailgate 118, as a unitary module with thecorresponding latch assembly 130. In one implementation, each latchactuator 154 is a motor-driven reduction drive. In this and otherimplementations, each latch actuator 154 is connected to the energysystem. Moreover, each latch actuator 154 may be connected with thecorresponding latch assembly 130. For each corresponding latch assembly130, latch 134 and latch actuator 154, using electrical energy from theenergy system 150, the latch actuator 154 is operable to activate thelatch 134 for non-revertible movement in the latching direction, anddeactivate the latch 134 for movement in the unlatching direction.Although the vehicle 100, as shown, includes one latch actuator 154 perlatch assembly 130, it will be understood that this disclosure isapplicable in principle to otherwise similar vehicles including one ormore latch actuators 154 per latch assembly 130.

The vehicle 100 can include one or more processors 144. In one or morearrangements, the processor(s) 144 can be a main processor(s) of thevehicle 100. For instance, the processor(s) 144 can be an electroniccontrol unit (ECU). The vehicle 100 can include one or more data stores327 for storing one or more types of data. The data store(s) 327 caninclude volatile and/or non-volatile memory. Examples of suitable datastore(s) 327 include RAM (Random Access Memory), flash memory, ROM (ReadOnly Memory), PROM (Programmable Read-Only Memory), EPROM (ErasableProgrammable Read-Only Memory), EEPROM (Electrically ErasableProgrammable Read-Only Memory), registers, magnetic disks, opticaldisks, hard drives, or any other suitable storage medium, or anycombination thereof. The data store(s) 327 can be a component of theprocessor(s) 144, or the data store(s) 327 can be operably connected tothe processor(s) 144 for use thereby.

The one or more data store(s) 327 can include sensor data 331. In thiscontext, “sensor data” means any information about the sensors that thevehicle 100 is equipped with, including the capabilities and otherinformation about such sensors. As will be explained below, the vehicle100 can include the sensor system 142. The sensor data 331 can relate toone or more sensors of the sensor system 142. As an example, in one ormore arrangements, the sensor data 331 can include information on thetailgate position sensor 379 of the sensor system 142.

The one or more data store(s) 327 can include lookup tables, equations,and other information stored so as to be accessible by sensors of thesensor system 142 and/or the tailgate control module 323 in performingthe operations described herein. For example, suitable lookup tables maybe used to estimate or determine a value of a motor accelerationparameter based on acquired values of a motor speed parameter or otherdata, as described herein.

In embodiments described herein, the memory 146 may be a random-accessmemory (RAM), read-only memory (ROM), a hard-disk drive, a flash memory,or other suitable memory for storing modules, such as the tailgatecontrol module 323. The tailgate control module 323 includes, forexample, computer-readable instructions that when executed by theprocessor 144, cause the processor(s) 144 to perform the variousfunctions disclosed herein. Additional modules (not shown) may also bestored in memory 146. For example, as part of a central control system,the vehicle 100 may include a global control unit (GCU) to with whichthe tailgate control module 323 is communicatively connected.

The vehicle 100 can include one or more modules, at least some of whichare described herein. The module(s) may be stored in memory 146. Themodules can be implemented as computer-readable program code that, whenexecuted by processor(s) 144, implement one or more of the variousprocesses described herein. One or more of the modules can be acomponent of the processor(s) 144, or one or more of the modules can beexecuted on and/or distributed among other processing systems to whichthe processor(s) 144 is operably connected. The modules can includeinstructions (e.g., program logic) executable by one or moreprocessor(s) 144. Alternatively, or in addition, one or more of datastore(s) 327 or another portion of the vehicle 100 may contain suchinstructions.

Generally, a module, as used herein, includes routines, programs,objects, components, data structures, and so on that perform particulartasks or implement particular data types. In further aspects, a memorygenerally stores the modules. The memory associated with a module may bea buffer or cache embedded within a processor, a RAM, a ROM, a flashmemory, or another suitable electronic storage medium. In still furtheraspects, a module as envisioned by the present disclosure is implementedas an application-specific integrated circuit (ASIC), a hardwarecomponent of a system on a chip (SoC), as a programmable logic array(PLA), or as another suitable hardware component that is embedded with adefined configuration set (e.g., instructions) for performing thedisclosed functions.

In one or more arrangements, one or more of the modules described hereincan include artificial or computational intelligence elements, e.g.,neural network, fuzzy logic or other machine learning algorithms.Further, in one or more arrangements, one or more of the modules can bedistributed among a plurality of the modules described herein. In one ormore arrangements, two or more of the modules described herein can becombined into a single module.

The processors 144, the memory 146 and the tailgate control module 323as described herein together may serve as a computing device whosecontrol module 323 is employable to orchestrate the operation of thetailgate 118. Specifically, the tailgate control module 323 may controloperation of the vehicle systems 140 based on information about thevehicle 100 (including the position and/or speed of the tailgate),received tailgate control signals, and other information. Accordingly,as a prerequisite to operating the tailgate, the control module 323gathers and/or receives information, including the information about thevehicle 100 detected by the sensor system 142. The control module 323may then evaluate the information and operate the various vehiclesystems and elements (including the tailgate 118) based on itsevaluation, with a view to controlling operations of the tailgate.

The vehicle 100 can include a tailgate control module (TGM) 323. Thetailgate control module 323 may be configured to receive tailgateopening and closing commands, and to automatically control opening andclosing operations of the tailgate 118. Embodiments of the tailgatecontrol module 323 as described herein may be configured to implement an“unsupervised mode” of automatic tailgate control whereby the tailgatemay be opened or remain closed depending on the magnitude of an externalload determined to be acting on the tailgate when the tailgate isclosed, and in cases where a user initiating the opening command may notbe located where he can visually inspect the closed tailgate. If thetailgate is automatically opened under the external load, the openingspeed may be monitored during opening. If the opening speed becomesexcessive, the control module 323 may control operation of the tailgateactuator to apply braking forces to slow the descent of the tailgate andprevent damage to the power tailgate system.

The tailgate control module 323 may include instructions that whenexecuted by the processor(s) 144 cause the processor(s) 144 to, eitheralone or in cooperation with the communications interface 383 and/orother portions of the vehicle or external to the vehicle, determinewhether or not a received tailgate opening command was generatedremotely. This determination may be based, for example, on an estimatedorigin point of a wireless command, or on a location of a human userwith respect to the vehicle 100 (for example, in the cab or next to thetailgate) for a wired command.

The tailgate control module 323 may include instructions that whenexecuted by the processor(s) 144 cause the processor(s) 144 to,responsive to a determination that a received tailgate opening commandwas not remotely generated, control operation of the actuator motor 210to open the tailgate 118 at a first predetermined tailgate openingspeed. The first predetermined tailgate opening speed may be a normalopening speed of the tailgate 118 in responding to a command toautomatically open the tailgate, and with no external load applied tothe tailgate 118. The tailgate control module 323 may be configured toassume, if the tailgate opening command is not remotely generated, thatthe user is able to visually inspect the cargo bed and tailgate todetermine whether or not an external load is being exerted on thetailgate. In this case, the tailgate control module may default to theuser's judgment regarding the viability of opening the tailgate and mayopen the tailgate responsive to the opening command.

The tailgate control module 323 may include instructions that whenexecuted by the processor(s) 144 cause the processor(s) 144 to,responsive to a determination that a received tailgate opening commandwas remotely generated, determine if an external load is being appliedto the tailgate when then tailgate is in a closed condition. Thedetermination may be made using the external load detection sensors 371,for example. The closed condition may include the tailgate 118 beinglatched by the latching mechanisms previously described. The tailgatecontrol module 323 may include instructions that when executed by theprocessor(s) 144 cause the processor(s) 144 to, responsive to adetermination that no external load is being applied to the tailgate 118when then tailgate is in the closed condition, control operation of theactuator motor 210 to open the tailgate at the first predeterminedtailgate opening speed.

An external load applied to a tailgate may be a load other than theforces acting on the tailgate 118 when the tailgate in the closedcondition and with no object in contact with the tailgate, either in thecargo bed 106 or outside the cargo bed. Thus, for example, the onlyforces normally acting on the tailgate without application of anexternal load may be tailgate support/connection forces exerted on thetailgate by the cargo bed at the hinge assembly and along the cargo bedwalls, and forces exerted by the latching assemblies and directed atmaintaining the tailgate in the closed condition as described herein.For example, FIG. 3 is a schematic side view of the vehicle 100 showingone possible application of a system for controlling a vehicle powertailgate 118 as described herein. As shown in FIG. 3 , one or more itemsof cargo 199 (such as a load of lumber or drywall) may have one end 199a resting on a floor of the cargo bed 106 and an opposite end 199 bresting on the tailgate 118 and extending out past the end of the cargobed. This cargo exerts an external load on the tailgate having avertical force component F1. The external load detection sensors 371 maybe configured to measure or estimate the value of the force F1 prior toopening the tailgate 118. The load may be a load which will continue toact on the tailgate after the latches are disengaged and the tailgatestarts to descend, and which will continue to act on the tailgatethroughout the opening process. If the vertical force component F1 issufficiently high, it may cause the tailgate to open more rapidly thandesired. This excessive opening speed may cause the motor to backdriveand may damage one or more elements of the tailgate system. A similarsituation may occur, for example, with a load hanging over the top 118 tof the tailgate and extending downwardly along a rear exterior surfaceof the tailgate. Such a load may tend to pull the tailgate downward atan excessive speed when the latches are disengaged and the tailgatestarts to descend.

The tailgate control module 323 may include instructions that whenexecuted by the processor(s) 144 cause the processor(s) to, responsiveto a determination that an external load is being applied to thetailgate 118 when then tailgate is in the closed condition, estimate amagnitude of the external load. The tailgate control module 323 may alsoinclude instructions to, responsive to an estimated magnitude of theexternal load being at or above a predetermined threshold load, maintainthe tailgate in a closed condition. The predetermined threshold load maybe an external load at or above which the tailgate actuator may not beable to work against to close the tailgate if needed after the tailgatehas started to open. The predetermined threshold load may be determinedanalytically and/or experimentally for a given vehicle/tailgate systemdesign. The tailgate control module 323 may be configured to, if theestimated external load applied to the tailgate 118 before openingequals or exceeds the predetermined threshold load, disobey a receivedtailgate opening command and forego unlatching and opening the tailgate,so as to prevent possible damage to the tailgate.

The tailgate control module 323 may also include instructions to,responsive to an estimated magnitude of the external load being belowthe predetermined threshold load, control operation of the motor tostart to open the tailgate at a second predetermined tailgate openingspeed different from the first predetermined tailgate opening speed. Thesecond predetermined tailgate opening speed may be an opening speed thatis slower than the first predetermined tailgate opening speed (or“normal” opening speed). This second predetermined opening speed may beused when it is determined that an external load is acting on thetailgate prior to opening, and the magnitude of the load is below thepredetermined threshold load. In one or more arrangements, the secondpredetermined opening speed may be set by a manufacturer of the vehicleor power tailgate system and may not be changed by an end-user. In otherarrangements, the second predetermined opening speed may be selectedfrom within a predetermined range by a user according to userpreferences. Opening the tailgate at a relatively slower opening speedwhen the tailgate is under external load may aid in restricting abuildup of momentum of the tailgate, in case opening of the tailgateneeds to be stopped prior to the tailgate completely opening.

The tailgate control module 323 may also include instructions to, afterthe motor 210 starts to open the tailgate at the second predeterminedtailgate opening speed, monitor the actual tailgate opening speed duringopening to determine if the actual opening speed rises to or above apredetermined threshold opening speed. The predetermined thresholdopening speed may be an opening speed at or above which damage may occurto the tailgate during opening and/or at the end of opening. The actualvalue of the predetermined threshold opening speed may vary withparticular vehicle and/or component designs and may be determined for aparticular vehicle configuration analytically and/or iteratively byexperimentation. For example, testing may be conducted to determine thetypes and/or extent of damage which may be caused by opening of thetailgate at various opening speeds caused by the loading describedherein. In one or more arrangements, for purposes of triggeringgeneration of a braking force as described herein, the predeterminedthreshold opening speed may be equal to or greater than the secondpredetermined tailgate opening speed. Thus, when it is intended to openthe tailgate at the second predetermined tailgate opening speed when thetailgate is under load, a determination that the second predeterminedtailgate opening speed is being exceeded may indicate that the magnitudeof the load is causing backdriving of the motor 210 and a more rapidopening of the tailgate which may result in damage to the tailgatesystem and vehicle.

The tailgate control module 323 may also include instructions to, aslong as the actual opening speed of the tailgate is not above thepredetermined threshold opening speed, continue to open the tailgate atthe second predetermined tailgate opening speed. If the actual openingspeed of the tailgate when under actuator motor power exceeds thepredetermined threshold opening speed, it may be assumed that theresultant force acting on the tailgate is producing an acceleration onthe tailgate that will cause an excessive terminal speed (i.e., a finalopening speed of the tailgate when the tailgate reaches the completelyopen position). This excessive terminal speed may cause damage to thetailgate system and vehicle.

The tailgate control module 323 may also include instructions to, if theactual opening speed rises to or above the predetermined thresholdopening speed, determine if a value of a motor speed parameter is at orabove a predetermined motor speed threshold and a value of a motoracceleration parameter is at or above a predetermined motor accelerationthreshold. The predetermined motor speed threshold and the predeterminedmotor acceleration threshold may represent critical values ofmotor-related parameters (such as rotation speed of the rotor and rotoracceleration/deceleration, for example) which are associated with theactual opening speed of the tailgate being at or above the predeterminedthreshold opening speed. Thus, the critical values of these parametersmay reflect operating conditions of the tailgate system under which therisk of damage to elements of the tailgate system and/or vehiclecomponents is greatly increased. The critical values of thepredetermined motor speed threshold and the predetermined motoracceleration threshold may take into consideration operating conditionsof the motor itself, and may reflect thresholds at or above whichdamage-free operation of the motor may be jeopardized.

The speed and acceleration of pertinent portions of the motor may becompared with these motor threshold values after the tailgate begins toopen. If the values of the motor speed parameter and the motoracceleration parameter rise above the predetermined motor speedthreshold and the predetermined motor acceleration threshold,respectively, the system may determine that the magnitude of theexternal load is such that a braking force must be applied to thetailgate to slow its descent, in order to prevent damage to the tailgatesystem and vehicle. The tailgate control module may then controloperation of the motor to apply a braking force to the tailgate. Controlof the motor to generate a braking force may include intermittently orcontinuously controlling the motor so as to tend to stop rotation of themotor. As seen in FIGS. 4A-4C, the braking may be applied in a binary“on” or “off” manner.

Critical values of the parameters to be used for decision-making may bedetermined analytically and/or iteratively through experimentation. Forexample, values of the predetermined motor speed threshold and thepredetermined motor acceleration threshold to be used for a particularapplication may be determined by the vehicle manufacturer, and maydepend on actuator motor characteristics, capabilities of theHall-effect sensor (or other sensor) used to determine motor rotationparameter values, the desired predetermined threshold opening speed fora given vehicle design, and a variety of other pertinent factors.

In a particular arrangement, the value of the predetermined motor speedthreshold may be 350 m/sec. The current motor speed parameter value maybe determined from rotor RPM using Hall sensor data, for example.

Application of the braking force has the effect of temporarily arrestingor slowing the opening of the tailgate, thereby interrupting what mayotherwise be a continued acceleration of the tailgate during opening.This is done with the intent of reducing the actual tailgate openingspeed to value below the predetermined threshold opening speed, whichmay also bring the motor speed parameter and the motor accelerationparameter to values below the predetermined motor speed threshold andthe predetermined motor acceleration threshold, thereby reducing thepossibility of damage. For example, if the tailgate is allowed toaccelerate continuously under the force of its own weight and the addedweight of an external load, the acceleration and terminal opening speedmay reach levels where the one or more elements of the tailgate systemmay be damaged at the end of opening. After the actuator motor parametervalues have been reduced by tailgate braking, the braking force may beremoved and the tailgate may be allowed to proceed with opening.

FIG. 4A is a schematic diagram showing one example of application of abraking force to a tailgate. The drawing shows the intermittentapplication of braking force during the period that the tailgate isopening. At point 402, the motor 210 may control the tailgate to startto open the tailgate. At point 404, the control module 323 may determinethat the actual tailgate opening speed has risen to a level at or abovethe predetermined threshold opening speed. The system may then determineif the current motor speed parameter value is at or above thepredetermined motor speed threshold and also if the current motoracceleration parameter value is at or above the predetermined motoracceleration threshold. If the current motor speed parameter value is ator above the predetermined motor speed threshold and the current motoracceleration parameter value is at or above the predetermined motoracceleration threshold, the motor 210 may be controlled to generate abraking force to be applied to the tailgate (i.e., the braking force mayswitch to an “on” condition and remain “on” “until it is determined thatthe current motor speed parameter value is below the predetermined motorspeed threshold and the current motor acceleration parameter value isbelow the predetermined motor acceleration threshold).

FIG. 4A shows the application of a braking force as needed to slow theopening speed of the tailgate whenever the current motor speed parametervalue is above the predetermined motor speed threshold and the currentmotor acceleration parameter value is above the predetermined motoracceleration threshold due to slowing of the tailgate descent (forexample, at point 406 of FIG. 4A). The motor may then be controlled (forexample, at point 406) to discontinue the braking force and the tailgatemay continue to open unbraked until another rise in motor parametervalues.

Referring again to FIG. 4A, as the tailgate once again builds up openingspeed, if the current motor speed parameter value is at or above thepredetermined motor speed threshold and the current motor accelerationparameter value is at or above the predetermined motor accelerationthreshold, another braking force may be applied to the tailgate (atpoint 408). This force may be maintained until (at point 410) thecurrent motor speed parameter value is below the predetermined motorspeed threshold and the current motor acceleration parameter value isbelow the predetermined motor acceleration threshold, at which point thebraking may be discontinued. This cycle may be repeated as needed tomaintain the opening speed below a certain level until the tailgatereaches the completely open position (at point 412). The motor speedparameter value and the motor acceleration parameter value may bemonitored continuously throughout the tailgate opening process andcompared with the applicable thresholds.

FIG. 4B is a schematic diagram showing another example of application ofa braking force to a tailgate. In this case, as in FIG. 4A, the brakingforce may be applied (at point 441) when it is determined that thecurrent motor speed parameter value is at or above the predeterminedmotor speed threshold and the current motor acceleration parameter valueis at or above the predetermined motor acceleration threshold. In thiscase, the braking force must be applied for a relatively longer timeperiod in order to reduce the current motor speed parameter value to avalue below the predetermined motor speed threshold and the currentmotor acceleration parameter value to a value below the predeterminedmotor acceleration threshold. Application of the braking force may thenbe discontinued at point 443, and the tailgate opening speed may notagain rise to the previous “pre-braking” level before the tailgatereaches the fully open condition (at point 445).

FIG. 4C is a schematic diagram showing yet another example ofapplication of a braking force to a tailgate. In this situation, thecontrol module 323 may control operation of the motor to apply a brakingforce continuously to the tailgate. Such braking may be used, forexample, in cases where the load acting on the tailgate is so large thata relatively short-term application of the braking force fails to reducethe current motor speed parameter value to a value below thepredetermined motor speed threshold and the current motor accelerationparameter value to a value below the predetermined motor accelerationthreshold. Continuous application of the braking force has the effect ofslowing the descent of the tailgate to the greatest degree possible withthe existing actuator(s) and during the entire time the tailgate isopening, in order to prevent damage to the tailgate system and vehicle.

For example, at point 420, the motor 210 may control the tailgate 118 tostart to open the tailgate. At point 422, the control module 323 maydetermine that is tailgate opening speed is above the predeterminedthreshold opening speed. The system may then determine if the motorspeed parameter value is at or above the predetermined motor speedthreshold and also if the motor acceleration parameter value is at orabove the predetermined motor acceleration threshold. If the motor speedparameter value is at or above the predetermined motor speed thresholdand the motor acceleration parameter value is at or above thepredetermined motor acceleration threshold, the tailgate control module323 may apply a braking force at point 422. However, since applicationof the braking force fails to sufficiently reduce the values of themotor speed parameter value and the motor acceleration parameter, thebraking force may be maintained until the tailgate is fully open (point424) to reduce the tailgate opening speed as much as possible.

The tailgate control module 323 may include instructions that whenexecuted by the processor(s) cause the processor(s) to control operationof the motor 210 so as to tend to stop a rotation of the motor, togenerate the braking force. A direction of rotation of the motor 210 maybe a direction of rotation of a rotor or an output shaft of the motor,for example, or a direction of rotation of any element of the motorwhich is operably coupled to the tailgate for opening/lowering andclosing/raising the tailgate. For example, the motor 210 may bestructured and operably connected to the tailgate 118 (by actuator andhinge assembly components as described herein) so that a rotation of themotor in a first direction may open the tailgate, while rotation of themotor in a second direction opposite the first direction may close thetailgate.

In one or more arrangements, a circuit of the motor 210 may be operableto apply a short circuit across the motor 210. Through application of ashort circuit, the motor circuit 203 is operable to electrically brakethe motor 210, whereupon the motor 210 resists being mechanically drivenfor spinning action (i.e., rotor rotation is impeded). This may have theeffect of braking the tailgate as the motor is back-driven by opening ata speed greater than the predetermined threshold opening speed. In oneparticular method of applying a short circuit to the motor, an H-bridgecircuit 297 with a pair of field effect transistors (FET's) 296 and 298may be used as shown in FIG. 5 . As is known, an H-bridge circuit may beemployed to switch the polarity of a voltage applied to a load. Othermethods of applying a short-circuit to the motor may also be used.

The processor(s) 144, the tailgate control module 323, and the memory146 can be operably connected to communicate with each other and withthe other elements of the vehicle, including various vehicle systems 140and/or individual components thereof.

Referring again to FIG. 1 , a sensor fusion algorithm 325 may be analgorithm (or a computing device storing an algorithm) configured toaccept data from the sensor system 142 as an input. The data mayinclude, for example, data representing information sensed at thesensors of the sensor system 142. The sensor fusion algorithm 325 mayinclude or be configured to be executed using, for instance, a Kalmanfilter, Bayesian network, or other algorithm. The sensor fusionalgorithm 325 may provide various assessments based on the data fromsensor system 142. Depending upon the embodiment, the assessments mayinclude evaluations of evaluations of particular situations and/orevaluations of possible impacts based on the particular situation. Otherassessments are possible. For example, the sensor fusion algorithm 325may evaluate information from the vehicle sensors, vehicle systems andother information from outside the vehicle (such as GPS information) todetermine whether a received tailgate opening command is remotelygenerated or locally generated.

As noted above, the vehicle 100 can include the sensor system 142. Thesensor system 142 can include one or more sensors. “Sensor” means anydevice, component and/or system that can detect, and/or sense something.The one or more sensors can be configured to detect, and/or sense inreal-time. As used herein, the term “real-time” means a level ofprocessing responsiveness that a user or system senses as sufficientlyimmediate for a particular process or determination to be made, or thatenables the processor to keep up with some external process. The sensorsystem 142 is operable to detect information about the vehicle 100. Inarrangements in which the sensor system 142 includes a plurality ofsensors, the sensors can work independently from each other.Alternatively, two or more of the sensors can work in combination witheach other. In such case, the two or more sensors can form a sensornetwork. The sensor system 142 and/or the one or more sensors can beoperably connected to the processor(s) 144, the data store(s) 327,and/or other element(s) of the vehicle 100 (including any of theelements shown in FIG. 1 ).

The sensor system 142 can include any suitable type of sensor. Variousexamples of different types of sensors will be described herein.However, it will be understood that the embodiments are not limited tothe particular sensors described. Various examples of sensors of thesensor system 142 are described herein. However, it will be understoodthat the embodiments are not limited to the particular sensorsdescribed. The sensor system 142 may include any sensors suitable forand/or required to perform any of the data acquisition and/or vehiclecontrol operations contemplated herein.

Sensors of sensor system 142 may be communicably coupled to the varioussystems and components of the vehicle 100. The sensors may be operablyconnected to the vehicle wireless communications interface 383 fortransmission of information to a cloud or other storage facility or forvehicle-to-vehicle (V2V) or vehicle-to-everything (V2X) communications.The sensors may also be operably connected to other vehicle systems andcomponents, such as data stores 327 and processor(s) 144, forcontrolling the tailgate 118 and other portions of the vehicle 100. Theexistence of any predetermined conditions described herein may becalculated or otherwise determined using sensor data.

Along with the sensors shown in FIG. 1 , the vehicle 100 may include oneor more additional tailgate-related sensors such as latch sensors (notshown), tailgate orientation or position sensors, and other sensorsrequired for the performance of the vehicle control operations describedherein. Relatedly, the sensor system 142 may be operable to detect, forexample, the movement of the tailgate 118, the operation of the latches134, requests to automatically open the tailgate 118, requests toautomatically close the tailgate 118, and the operational statuses ofone, some or all of the vehicle systems 140, including the energy system150, the tailgate actuator 122 and the latch actuators 154, and thevalues of tailgate-related parameters and the existence andnon-existence of various predetermined conditions.

In one or more arrangements, the sensor system 142 may include one ormore motor parameter sensors operably connected to the actuator motor210 and configured to detect or determine values of variousmotor-related operational parameters. In one or more arrangements, themotor parameter sensors may include a motor speed sensor 373 configuredto detect or determine a speed of the motor 210. A speed of the motormay be a rotational speed of a rotor of the motor, or the speed of anyelement of the motor which is operably coupled to the tailgate foropening/lowering and closing/raising the tailgate. Thus, the speed ofthe motor may be directly related to the tailgate opening speed. Themotor parameter sensors may also include a motor acceleration sensor 369configured to detect or determine an acceleration of the motor 210. Moreparticularly, the motor acceleration sensor 369 may be configured todetect rates of change in motor speed during opening of the tailgate.Alternatively, the tailgate control module 323 may be configured tocalculate or otherwise determine an acceleration of the motor based onchanges in motor speed over time and using formulae, lookup tables,and/or other information which may be stored in memory 146.

The sensor system 142 may include a tailgate opening speed sensor 377(for example, a suitably configured Hall Effect sensor) configured todetect or determine the opening speed the tailgate. The sensor system142 may include one or more external load detection sensors 371. Theexternal load detection sensors 371 may be configured for detectingand/or determining a magnitude and direction of any external load actingon the tailgate 118. Based on an estimated direction and magnitude of anexternal load applied to the tailgate before opening, a decision may bemade not to unlatch and open the tailgate, so as to prevent possibledamage to the tailgate.

The sensor system 142 may include one or more tailgate position sensors379 configured to detect an opening status of the tailgate (i.e.,whether the tailgate is closed, latched, partially open, fully open,etc.) and/or a rotational orientation or position of the tailgate (i.e.,the degree to which the tailgate is open or closed at any given point intime).

If needed, the sensor system 142 may include one or more tailgateopening signal detection sensor(s) 375 in communication with thewireless communications interface 383 and configured to aid indetermining or estimating the location of the received wireless tailgateopening command.

The vehicle 100 can include one or more vehicle systems, collectivelydesignated 140. Various examples of the one or more vehicle systems 140are shown in FIG. 1A. However, the vehicle 100 can include more, fewer,or different vehicle systems. It should be appreciated that althoughparticular vehicle systems are separately defined, each or any of thesystems or portions thereof may be otherwise combined or segregated viahardware and/or software within the vehicle 100.

The vehicle systems 140 may be operable to perform vehicle functions. Onbehalf of the vehicle system 140 to which it belongs, each vehicleelement is operable to perform, in whole or in part, any combination ofvehicle functions with which the vehicle system 140 is associated. Thevehicle systems 140 may be communicatively connected with the memory146, the tailgate actuator(s) 122, processor(s) 144, and any otherelements and systems of the vehicle 100 as needed to perform thetailgate control functions described herein.

The tailgate 118, latch assemblies 130, actuator(s) 122, control module323, and any sensors providing information relating to tailgateoperations may collectively define a power tailgate system of thevehicle 100. In addition, the vehicle systems 140 may include an energysystem 150. Elements of the power tailgate system may be connected tothe energy system 150. The energy system 150 may be operable to performone or more energy functions, including but not limited to storing andotherwise handling electrical energy. Elements of the power tailgatesystem may be operable to perform one or more tailgate control functionsusing electrical energy from the energy system 150, including but notlimited to automatically opening the tailgate 118 and automaticallyclosing the tailgate 118.

The vehicle 100 can include an input system 156. An “input system”includes any device, component, system, element or arrangement or groupsthereof that enable information/data to be entered into a machine. Forexample, the input system 156 may include a keypad, a touch screen orother interactive display, a voice-recognition system and/or any otherdevice or system which facilitates communications between a user and thevehicle. The input system 156 can receive wireless input from a vehicleoccupant (e.g., a driver or a passenger) or a user located remotely fromthe vehicle 100. For example, the input system may enable a user toinput tailgate control commands to the tailgate control module.

The vehicle 100 can also include an output system 158. An “outputsystem” includes any device, component, or arrangement or groups thereofthat enable information/data to be presented to a vehicle occupant(e.g., a driver, a vehicle passenger, etc.) or a remote user. Forexample, the output system may be operable to issue tactile, sound andvisual outputs that may be sensed by users. The output system may enablea user to receive alerts or other information relating to the position,speed, and other operating parameters of the tailgate.

The vehicle wireless communications interface 383 may be configured toenable and/or facilitate communication between the components andsystems of the vehicle and entities (such as cloud facilities, cellularand other mobile communications devices, other vehicles, remote servers,pedestrians, etc.) exterior of the vehicle. Wireless communicationsinterface 383 may be configured to facilitate, establish, maintain, andend wireless V2V and V2X communications with any extra-vehicular entity,for example other connectibly-configured vehicles and connectedvehicles, pedestrians, servers and entities located in the cloud, edgeservers, and other information sources and entities. User-initiatedcommands such as wireless tailgate opening commands may be received andother types of information may be transmitted and received via thecommunications interface 383. If required, wireless communicationsinterface 383 may incorporate or be in communication with any networkinterfaces needed to communicate with any extra-vehicular entitiesand/or networks.

In one or more arrangements, the wireless communications interface 383may be configured to determine or estimate a location of origin of areceived wireless tailgate opening command. This information may aid thetailgate control module in determining the location of a user withrespect to the vehicle, and thus whether the received tailgate openingcommand is locally generated or remotely generated. A tailgate openingcommand is a user-initiated command to open the tailgate. The tailgateopening command may be locally generated or remotely generated.

A locally generated tailgate opening command may be a command generatedwithin a predetermined distance from the tailgate and/or from a positionwithin a predetermined range of positions with respect to the tailgate.These distances from the tailgate and positions with respect to thetailgate may be determined or estimated so as to enable an assumptionthat the tailgate and the contents of the cargo bed are visible to ahuman user prior to the user generating a tailgate opening command, ifthe command is determined to be received from any of the predetermineddistances and/or positions. The tailgate control module 323 may beconfigured to assume that, if a tailgate opening command is receivedfrom any of the predetermined distances and/or positions, the user cansee what is in the cargo bed and any object that may be exerting anexternal load on the tailgate. Under these conditions, if the user stilldecides to open the tailgate even when an external load is acting on thetailgate, the tailgate control module may permit the tailgate to beopened at a first predetermined tailgate opening speed (or “normal”opening speed) responsive to the locally generated tailgate openingcommand. Locally generated opening commands may come from, for example,a keyfob (wireless) when the user is determined to reside in a locationwhere he can see the cargo bed and its contents, or the pressing of abutton located near the tailgate (wired).

A remotely generated tailgate opening command may be an opening commandgenerated from a distance or a position with respect to the tailgatethat is considered outside the ranges and/or positions prescribed forlocally generated commands. One example may be an opening commandgenerated from the vehicle occupant compartment. A user generating anopening command from the occupant compartment or cab may not be able tosee the cargo bed contents and an external load acting on the tailgate,and thus may not be aware of damage that may be caused by opening thetailgate when under external loading. Thus, if a remotely generatedopening command is received, the control module may determine if anexternal load is being applied to the tailgate.

If no external load is being applied to the tailgate, the tailgatecontrol module may control operation of the motor to open the tailgateat the normal opening speed responsive to the remotely generated openingcommand. However, if an external load is being applied to the tailgate,the tailgate control module may determine the magnitude of the load andcontrol operation of the motor as described herein to implement variousautomatic control operations directed to preventing damage to thetailgate due to the external loading. Remotely generated openingcommands may come from, for example, a keyfob (wireless) when the useris determined to not to reside in a location where he can see the cargobed and its contents, or the pressing of a button in the vehicle cab(wired) in a situation where the user may not be able to see the cargobed and its contents.

FIG. 6 is a flow diagram illustrating operation of a system forcontrolling a vehicle power tailgate in accordance with an embodimentdescribed herein.

In block 610, the tailgate control module 323 may receive a tailgateopening command. In block 612, the tailgate control module 323 maydetermine if the received tailgate opening command was remotelygenerated. If the received opening command was not remotely generated,the tailgate control module 323 may (in block 614) control operation ofthe actuator motor 210 to open the tailgate 118 at the firstpredetermined tailgate opening speed. However, if the received openingcommand was not remotely generated, the tailgate control module 323 may(in block 616) determine if an external load is being applied to atailgate when then tailgate is in the closed condition.

The tailgate control module 323 may (in block 614), if it is determinedin block 616 that no external load is being applied to the tailgate whenthen tailgate is in the closed condition, control operation of the motorto open the tailgate at the first predetermined tailgate opening speed.However, if it is determined in block 616 that an external load is beingapplied to the tailgate when then tailgate is in the closed condition,the tailgate control module 323 may (in block 618) estimate a magnitudeof the external load and compare the estimated magnitude of the load tothe predetermined threshold load. If the estimated magnitude of theexternal load is at or above the predetermined threshold load, thetailgate control module 323 may (in block 620) maintain the tailgate inthe closed condition in disobedience of the opening command. However, ifthe estimated magnitude of the external load is below the predeterminedthreshold load, the tailgate control module 323 may (in block 622)control operation of the motor to start to open the tailgate at thesecond predetermined tailgate opening speed.

After controlling the motor 210 to start to open the tailgate 118 at thesecond predetermined tailgate opening speed, the tailgate control module323 may (in block 624) continuously monitor the actual tailgate openingspeed to determine if the actual opening speed rises above thepredetermined threshold opening speed. As long as the actual openingspeed does not rise above the predetermined threshold opening speed, thetailgate control module 323 may (in block 626) control operation of themotor to continue to open the tailgate at the second predeterminedtailgate opening speed. However, if the actual opening speed rises abovethe predetermined threshold opening speed, the tailgate control module323 may (in block 628) determine if the value of the motor speedparameter is at or above the predetermined motor speed threshold and thevalue of the motor acceleration parameter is at or above thepredetermined motor acceleration threshold.

If the value of the motor speed parameter is at or above thepredetermined motor speed threshold and the value of the motoracceleration parameter is at or above the predetermined motoracceleration threshold, the tailgate control module 323 may (in block630) control operation of the motor 210 to apply a braking force to thetailgate, in a manner previously described. If a braking force is notbeing applied to the tailgate when it is determined that the value ofthe motor speed parameter is at or above the predetermined motor speedthreshold and the value of the motor acceleration parameter is at orabove the predetermined motor acceleration threshold, the motor may becontrolled to initiate application of a braking force. If a brakingforce is being applied to the tailgate and it is determined that thevalue of the motor speed parameter is still at or above thepredetermined motor speed threshold and the value of the motoracceleration parameter is still at or above the predetermined motoracceleration threshold, the motor may be controlled to continueapplication of the braking force.

In block 632, the tailgate control module 323 may (using data fromtailgate position sensor(s) 379) determine of the tailgate is fullyopen. If the tailgate is fully open, there is no further need for thebraking force and tailgate control module 323 may (in block 634) controloperation of the motor to discontinue application of the braking forceto the tailgate. However, if the tailgate is not fully open, control mayloop back to block 628, where it may be determined if the value of themotor speed parameter is still at or above the predetermined motor speedthreshold and the value of the motor acceleration parameter is still ator above the predetermined motor acceleration threshold.

If the value of the motor speed parameter is still at or above thepredetermined motor speed threshold and the value of the motoracceleration parameter is still at or above the predetermined motoracceleration threshold, blocks 630-632 may be repeated. However, if itis determined that the value of the motor speed parameter is below thepredetermined motor speed threshold and the value of the motoracceleration parameter is below the predetermined motor accelerationthreshold, tailgate control module 323 may (in block 636) controloperation of the motor to discontinue application of the braking forceto the tailgate.

In the manner just described, the motor 210 may be controlled to apply abraking force to the tailgate whenever the value of the motor speedparameter is at or above the predetermined motor speed threshold and thevalue of the motor acceleration parameter is at or above thepredetermined motor acceleration threshold, and to discontinueapplication of the braking force when the value of the motor speedparameter is below the predetermined motor speed threshold and the valueof the motor acceleration parameter is below the predetermined motoracceleration threshold.

Values of the actual tailgate opening speed (for comparison to thepredetermined threshold opening speed) and associated values of theactuator motor speed and acceleration parameters (for comparison withthe predetermined motor speed threshold and the predetermined motoracceleration threshold) may be continuously determined and updatedduring descent of the tailgate to the fully open position.

Detailed embodiments are disclosed herein. However, it is to beunderstood that the disclosed embodiments are intended only as examples.Therefore, specific structural and functional details disclosed hereinare not to be interpreted as limiting, but merely as a basis for theclaims and as a representative basis for teaching one skilled in the artto variously employ the aspects herein in virtually any appropriatelydetailed structure. Further, the terms and phrases used herein are notintended to be limiting but rather to provide an understandabledescription of possible implementations. Various embodiments are shownin FIGS. 1-5B, but the embodiments are not limited to the illustratedstructure or application.

The flowcharts and block diagrams in the figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments. In this regard, each block in the flowcharts or blockdiagrams may represent a module, segment, or portion of code, whichcomprises one or more executable instructions for implementing thespecified logical function(s). It should also be noted that, in somealternative implementations, the functions noted in the block may occurout of the order noted in the figures. For example, two blocks shown insuccession may, in fact, be executed substantially concurrently, or theblocks may sometimes be executed in the reverse order, depending uponthe functionality involved.

The systems, components and/or processes described above can be realizedin hardware or a combination of hardware and software and can berealized in a centralized fashion in one processing system or in adistributed fashion where different elements are spread across severalinterconnected processing systems. Any kind of processing system oranother apparatus adapted for carrying out the methods described hereinis suited. A typical combination of hardware and software can be aprocessing system with computer-usable program code that, when beingloaded and executed, controls the processing system such that it carriesout the methods described herein. The systems, components and/orprocesses also can be embedded in a computer-readable storage, such as acomputer program product or other data programs storage device, readableby a machine, tangibly embodying a program of instructions executable bythe machine to perform methods and processes described herein. Theseelements also can be embedded in an application product which comprisesall the features enabling the implementation of the methods describedherein and, which when loaded in a processing system, is able to carryout these methods.

Furthermore, arrangements described herein may take the form of acomputer program product embodied in one or more computer-readable mediahaving computer-readable program code embodied, e.g., stored, thereon.Any combination of one or more computer-readable media may be utilized.The computer-readable medium may be a computer-readable signal medium ora computer-readable storage medium. The phrase “computer-readablestorage medium” means a non-transitory storage medium. Acomputer-readable storage medium may be, for example, but not limitedto, an electronic, magnetic, optical, electromagnetic, infrared, orsemiconductor system, apparatus, or device, or any suitable combinationof the foregoing. More specific examples (a non-exhaustive list) of thecomputer-readable storage medium would include the following: a portablecomputer diskette, a hard disk drive (HDD), a solid-state drive (SSD), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a portable compact disc read-only memory (CD-ROM), adigital versatile disc (DVD), an optical storage device, a magneticstorage device, or any suitable combination of the foregoing. In thecontext of this document, a computer-readable storage medium may be anytangible medium that can contain, or store a program for use by or inconnection with an instruction execution system, apparatus, or device.

Generally, modules as used herein include routines, programs, objects,components, data structures, and so on that perform particular tasks orimplement particular data types. In further aspects, a memory generallystores the noted modules. The memory associated with a module may be abuffer or cache embedded within a processor, a RAM, a ROM, a flashmemory, or another suitable electronic storage medium. In still furtheraspects, a module, as envisioned by the present disclosure, isimplemented as an application-specific integrated circuit (ASIC), ahardware component of a system on a chip (SoC), as a programmable logicarray (PLA), or as another suitable hardware component that is embeddedwith a defined configuration set (e.g., instructions) for performing thedisclosed functions.

Program code embodied on a computer-readable medium may be transmittedusing any appropriate medium, including but not limited to wireless,wireline, optical fiber, cable, RF, etc., or any suitable combination ofthe foregoing. Computer program code for carrying out operations foraspects of the present arrangements may be written in any combination ofone or more programming languages, including an object-orientedprogramming language such as Java™, Smalltalk, C++ or the like andconventional procedural programming languages, such as the “C”programming language or similar programming languages. The program codemay execute entirely on the user's computer, partly on the user'scomputer, as a stand-alone software package, partly on the user'scomputer and partly on a remote computer, or entirely on the remotecomputer or server. In the latter scenario, the remote computer may beconnected to the user's computer through any type of network, includinga local area network (LAN) or a wide area network (WAN), or theconnection may be made to an external computer (for example, through theInternet using an Internet Service Provider).

The terms “a” and “an,” as used herein, are defined as one or more thanone. The term “plurality,” as used herein, is defined as two or morethan two. The term “another,” as used herein, is defined as at least asecond or more. The terms “including” and/or “having,” as used herein,are defined as comprising (i.e., open language). The phrase “at leastone of . . . and . . . ” as used herein refers to and encompasses anyand all possible combinations of one or more of the associated listeditems. As an example, the phrase “at least one of A, B, and C” includesA only, B only, C only, or any combination thereof (e.g., AB, AC, BC orABC).

Aspects herein can be embodied in other forms without departing from thespirit or essential attributes thereof. Accordingly, reference should bemade to the following claims, rather than to the foregoingspecification, as indicating the scope hereof.

What is claimed is:
 1. A system for controlling a vehicle power tailgate comprising: a motor operably connectible to a tailgate to open and close the tailgate; a processor; and a memory communicably coupled to the processor and storing a tailgate control module including instructions that when executed by the processor cause the processor to, responsive to a value of a motor speed parameter being at or above a predetermined motor speed threshold and a value of a motor acceleration parameter being at or above a predetermined motor acceleration threshold during opening of a tailgate, control operation of the motor to apply a braking force to the tailgate.
 2. The system of claim 1 wherein the tailgate control module includes instructions that when executed by the processor cause the processor to control operation of the motor to apply the braking force until the value of the motor speed parameter is no longer at or above the predetermined motor speed threshold and the value of the motor acceleration parameter is no longer at or above the predetermined motor acceleration threshold.
 3. The system of claim 1 wherein the tailgate control module includes instructions that when executed by the processor cause the processor to control operation of the motor so as to tend to stop a rotation of a rotor of the motor to generate the braking force.
 4. The system of claim 3 wherein the tailgate control module includes instructions that when executed by the processor cause the processor to control operation of the motor to generate the braking force by applying a short circuit to the motor so as to impede rotation of the rotor.
 5. The system of claim 1 wherein the tailgate control module includes instructions that when executed by the processor cause the processor to, responsive to a determination that a received tailgate opening command was not remotely generated, control operation of the motor to open the tailgate at a first predetermined tailgate opening speed.
 6. The system of claim 1 wherein the tailgate control module includes instructions that when executed by the processor cause the processor to: responsive to a determination that a received tailgate opening command was remotely generated, determine if an external load is being applied to a tailgate when then tailgate is in a closed condition; and responsive to a determination that no external load is being applied to the tailgate when the tailgate is in the closed condition, control operation of the motor to open the tailgate at a first predetermined tailgate opening speed.
 7. The system of claim 6 wherein the tailgate control module includes instructions that when executed by the processor cause the processor to: responsive to a determination that an external load is being applied to the tailgate when the tailgate is in the closed condition, estimate a magnitude of the external load; and responsive to an estimated magnitude of the external load being at or above a predetermined threshold load, maintain the tailgate in the closed condition.
 8. The system of claim 6 wherein the tailgate control module includes instructions that when executed by the processor cause the processor to: responsive to a determination that an external load is being applied to the tailgate when the tailgate is in the closed condition, estimate a magnitude of the external load; and responsive to an estimated magnitude of the external load being below a predetermined threshold load, control operation of the motor to start to open the tailgate at a second predetermined tailgate opening speed different from the first predetermined tailgate opening speed.
 9. The system of claim 8 wherein the tailgate control module includes instructions that when executed by the processor cause the processor to: determine an actual opening speed of the tailgate; if the actual opening speed is at or above a predetermined threshold opening speed, determine if the value of the motor speed parameter is at or above the predetermined motor speed threshold and if the value of the motor acceleration parameter is at or above the predetermined motor acceleration threshold; and if the actual opening speed is less than the predetermined threshold opening speed, continue controlling operation of the motor to open the tailgate at the second predetermined tailgate opening speed.
 10. A method of controlling a vehicle power tailgate system including a motor operably connectible to a tailgate to open and close the tailgate, the method comprising steps of: responsive to a value of a motor speed parameter being at or above a predetermined motor speed threshold and a value of a motor acceleration parameter being at or above a predetermined motor acceleration threshold during opening of a tailgate, controlling operation of the motor to apply a braking force to the tailgate; and responsive to the value of the motor speed parameter being below the predetermined motor speed threshold and the value of the motor acceleration parameter being below the predetermined motor acceleration threshold during opening of a tailgate, controlling operation of the motor to discontinue application of a braking force to the tailgate.
 11. The method of claim 10 wherein the step of controlling operation of the motor to apply the braking force to the tailgate comprises controlling operation of the motor so as to tend to stop a rotation of a rotor of the motor.
 12. The method of claim 11 wherein the step of controlling operation of the motor to apply the braking force to the tailgate comprises controlling operation of the motor to generate the braking force by applying a short circuit to the motor so as to impede rotation of the rotor.
 13. The method of claim 10 further comprising a step of responsive to a determination that a received tailgate opening command was not remotely generated, controlling operation of the motor to open the tailgate at a first predetermined tailgate opening speed.
 14. The method of claim 10 further comprising steps of: responsive to a determination that a received tailgate opening command was remotely generated, determining if an external load is being applied to a tailgate when then tailgate is in a closed condition; and responsive to a determination that no external load is being applied to the tailgate when the tailgate is in the closed condition, controlling operation of the motor to open the tailgate at a first predetermined tailgate opening speed.
 15. The method of claim 14 further comprising steps of: responsive to a determination that an external load is being applied to the tailgate when the tailgate is in the closed condition, estimating a magnitude of the external load; and responsive to an estimated magnitude of the external load being above a predetermined threshold load, maintaining the tailgate in the closed condition.
 16. The method of claim 14 further comprising steps of: responsive to a determination that an external load is being applied to the tailgate when the tailgate is in the closed condition, estimating a magnitude of the external load; and responsive to an estimated magnitude of the external load being at or below a predetermined threshold load, controlling operation of the motor to start to open the tailgate at a second predetermined tailgate opening speed different from the first predetermined tailgate opening speed.
 17. The method of claim 16 further comprising steps of: determining an actual opening speed of the tailgate; if the actual opening speed is greater than a predetermined threshold opening speed, determining if the value of the motor speed parameter is above the predetermined motor speed threshold and if the value of the motor acceleration parameter is above the predetermined motor acceleration threshold; and if the actual opening speed is less than or equal to the predetermined threshold opening speed, continuing to control operation of the motor to open the tailgate at the second predetermined tailgate opening speed.
 18. A non-transitory computer-readable medium for controlling a vehicle power tailgate system including a motor operably connectible to a tailgate to open and close the tailgate, the medium storing instructions that when executed by one or more processors cause the one or more processors to: responsive to a value of a motor speed parameter being at or above a predetermined motor speed threshold and a value of a motor acceleration parameter being at or above a predetermined motor acceleration threshold during opening of a tailgate, controlling operation of the motor to apply a braking force to the tailgate; and responsive to the value of the motor speed parameter being below the predetermined motor speed threshold and the value of the motor acceleration parameter being below the predetermined motor acceleration threshold during opening of a tailgate, controlling operation of the motor to discontinue application of a braking force to the tailgate.
 19. The non-transitory computer-readable medium of claim 18, wherein the instructions further include instructions to control operation of the motor to generate the braking force by applying a short circuit to the motor so as to impede rotation of a rotor of the motor. 